Thought maybe some of you could help me out on this. I've got a 95 Ford F150 4.9L, and currently I'm having a problem with it getting close to overheating. The last couple of days I've noticed the temp gauge getting close to the red mark while sitting still in traffic. If I'm on the highway or moving the gauge goes back down. This morning on the way to work I also noticed that when I turned on the heat, I was getting cold air only.

I'm thinking that the whole problem is a busted thermostat, right or wrong? Does anyone have any suggestions on maybe something else being wrong? I'm hoping this does not turn into two seperate problems. Let me know what you all think. Thanks ahead of time!!

 

Water will by-pass the thermostat to your heater core so if you're not getting any heat...sounds more like a clogged radiator...try radiator cleaner following the directions and then reverse flush the radiator. Someone may have put city water in the rad, which after time will cause deposits of crap, especially in an aluminum radiator. Remember to always use distilled water with an aluminum approved anti-freeze (which most are Ethylene Glycol )

 

Same thing happened on my 94 4.9 it was no problem with the thermostat or anything like that but heck you might want to replace it anyway for a low temp one. IT ended up being my fan clutch being crapped out and not engaging the fan when stopped or in traffic.

 

Thanks for the help guys. I'm going to get it flushed out here very soon. If that does not work then I'll try some other stuff. Question for you though, the fan does not run all the time? I thought it ran on a constant basis for this engine. Well, at least I'm learning about the 4.9L, lol. Thanks again guys!!

 

The fan does run all the time but when stopped in traffic or at slower speeds when the truck is warm the fan runs faster to blow air over the engine faster cooling it, when at higher speeds the fan does not run as fast. Yea the website has been good for me as well learnin about the 4.9

 

I ran a radiator shop for several years and saw these problems a lot. This sounds like two seperate problems. First the overheating, like others have said it sounds like a fan clutch problem. At highway speeps you could run without a fan but in traffic the radiator depends on air pull through by the fan. Crank the truck and warm it up then have someone speed up the motor and let it slow down. If it doesn't appear that the fan speed changes, change the clutch. Next for the heater, warm up the truck and turn on the heater. Feel of both heater hoses. If one is hot and the other one is noticably cooler, it's a stopped up heater core. When the heater core is stopped up it will slow the water through the core and it will act like a small radiator and actually have time to cool the water.

 

Sorry it took me so long to reply here, I thought I posted up what I found. I wanted to close the case for any others who may run into the same problem. I found a leak coming from the front of the engine so after my last post on here. After searching around on the front of the engine for a while, I tried to figure out if my leak was coming from the t-stat housing or the water pump. Friend of mine grabbed the upper hose and found that the clamp was super loose. Tighten it up, filled the radiator back up, and everthing was back to normal. Had heat again in the cab, and the temp gauge did not go past the R in normal. Problem solved right?, NOPE. About week later, I noticed a leak again under the truck, but no heating issues. Checked it out closer and found once again another anit-freeze leak (errrrrrrrrr). I crawed under the truck while it was running and it looked like someone was pouring it out from a cup down the front of the engine. Determined it was the water pump, which might have just been a loose bolt on the bottom of the water pump . I replaced the water pump anyway since I had everything out, seemed like the smartest move. Since then no more leaks, or anything else has gone wrong, at least for now. Anyway, problem solved thank god, and thanks again guys for the help/suggestions!!